How can I do this

[little-soldier]

hello everyone,
Right now I have my exhaust fan on a solid state speed controller so I can have it run at about half speed. The problem is sometimes I want it at full speed like when the room gets too hot so how can I go about doing this?
thx

 

[Bush Grower]

Look in the DIY sticky in this forum. I believe theres a post where you can make your own. Or you can buy one online.. I have seen them on hydro store websites

 

[PharmaCan]

Uh, turn the controller all the way up. LOL

Seriously, won't the solid state speed controller go up to all the way on? (That's probably a stupid question, but if it won't go up to 100%, explain why as that might have something to do with the solution to your problem.)

If the controller won't go up to 100%, the easiest thing to do would be to wire a switch that bypasses the controller. All you need to do is add a jumper to the hot line on either side of the controller then put an on/off switch in between the jumpers. Obviously this should be done consistent with accepted wiring standards.

PC

 

[DangerP]

I think little-soldier means he wants it to adjust the airflow automatically. Changing the fan speed manually is useful, but only if you happen to be in the room when it gets too hot.

I can think of a couple of ways to do this, but they all involve soldering and are kludgy as hell. Unless you're very good with a soldering iron (a damn sight better than me) soldering surface mount traces like they have inside those speed controllers is a large order. Basically I would either build something that would move the dial mechanically, or I would open it up to see what the dial controls and make a temperature controlled version of that. I'm guessing that the dial is a rheostat, which is basically a resister that changes it resistance based on how the dial is turned. If that's the case you can build something to replace it with that changes resistance based on the temperature.

Honestly, though, I'm really bad with that kind of thing, so I would find a friendly electrical engineer and bribe them with weed. That's what I would do.

After reading this post it occurs to me that it's probably completely useless, but I'll throw it up here anyway. Maybe it's helpful. I'm high.

 

[little-soldier]

if i have to solder then i guess i will have to buy something that does this. what do i have to look for?

 

[Pseudo]

id go buy an attic fan thermostat and run another power lead to the fan, that way its on half all the time, until the room heats up and then it goes 100%

 

[Murphy]

id go buy an attic fan thermostat and run another power lead to the fan, that way its on half all the time, until the room heats up and then it goes 100%

That's a short dude, you would need a relay to switch power from one device to the other, if both were powered at the same time, you're going to have sparks.

You need to look for a variable speed controler base on temp. The higher the temp, the higher the speed......can't say I know where to find one but I would think that there were uses for them.

 

[robbiedublu]

Any particular reason why you just don't want to run it full speed all the time?

 

[00420]

variable speed controler based on temp

^google this

get this Results 1 - 10 of about 586,000 for variable speed controller based on temp. (0.16 seconds)

http://www.greenhousemegastore.com/prodinfo.asp?number=CT-VC-5120P

that was just the first one ^^^^^^^^^^^^^^....

 

[little-soldier]

Cool, now I have a better idea of what to look for. Your help has been very helpfull guys and is very well appreciated
have a good one every1

 

[Pseudo]

murph
theres only one device being powered

 

[Murphy]

murph
theres only one device being powered

Right, one device being powered by 2 different power supplies if I undestood you correctly. In your idea, what is cutting power from one source before it turns the other source on? otherwise, you're going to short out....or worse.

 

[Pseudo]

as long as neutral goes to neutral and hot to hot, its still only 110 volts, if you reverse them i believe its 220,and thats when you run into problems, right?

 

[PharmaCan]

In a word, no. And what you are proposing might work, it might not. It all depends on where the breakers for the various lines you are proposing are located in the panel.

... and which is why you should leave electrical advice to those who know what they are talking about. There are a number of good electricians on this forum, so it's not like posters are wanting for competent assistance.

PC

 

[Pseudo]

i dont remember proposing anything, this is a discussion, its how you learn, and dont tell me the answer is no when you yourself obviously dont know the answer

 

[PharmaCan]

i dont remember proposing anything, this is a discussion, its how you learn, and dont tell me the answer is no when you yourself obviously dont know the answer

You're right! I'm just a dumb-shit going around posting BS I know nothing about just so people will think I'm smart. Hell, I wouldn't know a piece of wire if it came up and poked me in the eye.

Thanks for setting me straight. I hate it when my ego gets so out of control.

PC

 

[Pseudo]

no prob, dont beat yourself up over it